Thanks, yes I do see now, it looks simple this way.
I go read the akabak manual extensively and see what I can do.
for the conic sybergy I use now hornresp who is good enough for that, tractrix it can but not well and no export.
regards kees
I go read the akabak manual extensively and see what I can do.
for the conic sybergy I use now hornresp who is good enough for that, tractrix it can but not well and no export.
regards kees
I did see that when use a closed rear box the woofers get quick run out of Xmax (5mm) below 100 hz, a second reflex port do wonders here, I do not now it hornresp do 5 mm : 2 = 2.5 mm, because then I have to fill in 10 mm.
You has a script for the bigger horn, do you also have one for the smaller one, do fit here a 8 inch woofer, or maybe a 6 incher who do work also fine.
regards
kees
You has a script for the bigger horn, do you also have one for the smaller one, do fit here a 8 inch woofer, or maybe a 6 incher who do work also fine.
regards
kees
I use same script for smaller 0.7x horn with exception of a 0.7x scaling constant applied to all dimensional variables. I also made the back chamber volume smaller.
Nice! 😀 Interesting to see how those woofers like it. Whats the compression ratio of those ports?
Without a backchamber they are not going to sound too "horny" or punchy. My experiance was that the sound changed dramatically when I put the back chambers on properly.
Without a backchamber they are not going to sound too "horny" or punchy. My experiance was that the sound changed dramatically when I put the back chambers on properly.
Those drivers are high Qts of about 1 and would need a very large back chamber. They seem to sound nice in slot loaded OB so this injection port is kind of like that. Comp ratio may be a bit high at 5:1 but I did not way to make such big ports. I can always take a razor to it.
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Slots and horn loading ought to increase their Q even higher. Maybe some "controlled leaking" (aperiodic) back chambers could work in small size if you want to test things out.
Needs a sealed back...
Legis,
I just had time to model this Synergy with the quad 6.5in woofers. I think you are right, I will need to put a box over the drivers to get any bass out of them. Their proximity is too close to the mouth and the front and rear waves just cancel. Maybe if I had a large baffle panel to put the mouth in then it would be different but that ruins the cool look of the drivers sticking out. At least with the boxes, it still retains this industrial mechanized look. The box doesn't need to be big, in fact, too big and bass is not good. So a 8 in deep x 14 in wide x 6 in tall box for 11 liters on top and 11 liters on bottom should do the trick.
Here are results of sim - I should be able to cover about 100Hz to 18kHz with the qnty 4 buyout 6.5in woofers and the TC9FD with a system sensitivity of about 96dB at 1m and 2.83v.
SPL vs Freq at 2.83v with 90Hz HPF on woofers and 300Hz LPF on woofers, 350Hz HPF on TC9FD:
xmax of 3.5mm is reached at 21volts and gives this for the cone displacement:
With the resulting max SPL capability limited by xmax at about 113dB:
Here is the corresponding max electrical power required for the TC9FD (black) and the woofers (red) - about 30 watts to each driver which matches their thermal rating. Wait, I don't even have an amplifier more powerful than 80 watts at 4 ohms... 😀
Legis,
I just had time to model this Synergy with the quad 6.5in woofers. I think you are right, I will need to put a box over the drivers to get any bass out of them. Their proximity is too close to the mouth and the front and rear waves just cancel. Maybe if I had a large baffle panel to put the mouth in then it would be different but that ruins the cool look of the drivers sticking out. At least with the boxes, it still retains this industrial mechanized look. The box doesn't need to be big, in fact, too big and bass is not good. So a 8 in deep x 14 in wide x 6 in tall box for 11 liters on top and 11 liters on bottom should do the trick.
Here are results of sim - I should be able to cover about 100Hz to 18kHz with the qnty 4 buyout 6.5in woofers and the TC9FD with a system sensitivity of about 96dB at 1m and 2.83v.
SPL vs Freq at 2.83v with 90Hz HPF on woofers and 300Hz LPF on woofers, 350Hz HPF on TC9FD:
xmax of 3.5mm is reached at 21volts and gives this for the cone displacement:
With the resulting max SPL capability limited by xmax at about 113dB:
Here is the corresponding max electrical power required for the TC9FD (black) and the woofers (red) - about 30 watts to each driver which matches their thermal rating. Wait, I don't even have an amplifier more powerful than 80 watts at 4 ohms... 😀
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Progress with 90 minutes of work...
Still need to wire it up series parallel for 4 ohms nominal on woofers (PE buyout 6.5in polycone woofers $5 ea).
This will be fun, a $40 Synergy 😀
nice looking one.
Oke, I have done some search about vtc, it is as I tought, total front speaker chamber volume, and atc is Sd as start.
Well the use of a clearance plate between speaker and baffle with port do increase the volume to much, I have now the idea to mill clearance in the baffle itselfs so surround do not touch baffle for bass woofers.
The Xmax can be repaired by use a bassrefex port tuned on the low desired frequenty, where cone will be damped, a high pass filter is needed below that where the speaker get unloaded again.
I hope this story will give some hope guys that I get it slowly.
thanks for all the help and sorry I was so write addiced.
some examples what I mean with sinking speaker in baffle
regards
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Kees,
that is standard practice with Synergy builds to mill a circular clearance groove for the surround not to rub. You may want to consider putting a "frustrum" or file down the inside of the port hole so that it is conical tapering to exit port. This gives less HF interference to the HF driver, My foam core is so thin I have to add a spacer ring. Hope you build it. I have to say that with foam core, I have been able to move pretty fast with this and able to get some instant gratification... 🙂
that is standard practice with Synergy builds to mill a circular clearance groove for the surround not to rub. You may want to consider putting a "frustrum" or file down the inside of the port hole so that it is conical tapering to exit port. This gives less HF interference to the HF driver, My foam core is so thin I have to add a spacer ring. Hope you build it. I have to say that with foam core, I have been able to move pretty fast with this and able to get some instant gratification... 🙂
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Yes I now what you mean, I had a answer from David also about the VTC problem, he tell me also when use two woofers hornresp do not take that in account for the VTC and have to multiply it, however when I do this I get a very nasty respons and it go not to 1000 Hz any, anymore, this will say I have to fill up the space in the chamber but there is a port in it and when make longer it give also a nasty peak, How did you get around with that in akabak? because also there I presume it is a problem, or not because you use max 500 hz for the woofers and maybe you get away with it that way, To find out what the phillips do I can try them in your script but need then to make VTC bigger woofer phillips is 0.448 liters cone room.
When make the horn laike you have I use very thin wood of special quality and glue them together on a wooden template, I did it before, strong stuff.
regards
kees
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Kees,
Yes, there is a resonance peak corresponding to the injection port and front chamber volume. In Akabak, I use multiple front chambers, one for each driver so not a problem. I don't have to fudge the Vtc to pretend that there are multiple drivers. If you increase Vtc to simulate multiple drivers, you also need to increase Atc to scale with number of drivers. If you don't do that, the resonance peak will shoot up.
Here is the response of my 4 woofers in the Tractrix without a LPF. There is a peak around 650Hz and 1100hz, which is why I set LPF at 300Hz.
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Yes it looks good, however in my case when the conic synergy has a tweeter in it I need high respons of woofers and get this easy with small VTC value make it act more like a compression driver, do I am right? so a fase plug in the woofers cone space will work fin, however I need one who not affect the horn port.
On this site are some who I can use for it, but it makes port longer and so I get peaks.
Phase Plugs
I have rise ATC to 2 x Sd also as a start because of wood thickness.
regards
kees
On this site are some who I can use for it, but it makes port longer and so I get peaks.
Phase Plugs
I have rise ATC to 2 x Sd also as a start because of wood thickness.
regards
kees
Kees,
Was that your horn pictured? If it is, I was following your posts way back when you were making this.
X
No it is not from me but from Thijs, I have steal the picture from him as example, I hope he do not mind.
I have 4 phillips old speakers I do want to use them, do very well, I use only two she are 8 inch.
can you tell me where you put the VTC ATC in your script ? so I can test what it really does, akabak
is afcourse a little different.
regards
kees
I have 4 phillips old speakers I do want to use them, do very well, I use only two she are 8 inch.
can you tell me where you put the VTC ATC in your script ? so I can test what it really does, akabak
is afcourse a little different.
regards
kees
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Kees,
In the script for the 'Kappalite' mids you find this section of code. 'Driver Chamber 1' 'vol_driver_chmber' is Vtc, and 'Injection Port 1' 'dD'={Dia_inj} is the Atc.
In the script for the 'Kappalite' mids you find this section of code. 'Driver Chamber 1' 'vol_driver_chmber' is Vtc, and 'Injection Port 1' 'dD'={Dia_inj} is the Atc.
Code:
| *** bass drivers ***
| Define driver to be used and wired in parallel (left driver when viewed from front
Driver Def='Kappalite12' 'Driver 1'
Node=1=0=111=201
| Right driver when viewed from front
Driver Def='Kappalite12' 'Driver 2'
Node=1=0=112=202
| *** option to put chambers with ducts leading to horn injection point ***
Enclosure 'Driver Chamber 1' Node=111
Vb={Vol_driver_chmber} Qb/fo={Q_ch_front} Lb=4in | keep chamber very flat - circa 1 in from cone to port
| *** duct from driver 1 compression chamber to horn injection point ***
Duct 'Inject Port 1' Node=111=56
dD={Dia_inj} Len=0.719in | Thickness of wall plywood
Enclosure 'Driver Chamber 2' Node=112
Vb={Vol_driver_chmber} Qb/fo={Q_ch_front} Lb=4in
| *** duct from driver 2 compression chamber to horn injection point ***
Duct 'Inject Port 2' Node=112=56
dD={Dia_inj} Len=0.719in | Thickness of wall plywoodYou say it yourselfs, keep the chamber very flat, but speaker has a cone with room in it that is what makes the volume cone has to be included in my case 0.448 liters.
I have done a kind of plug, I do not now what happens when use it it fills room of woofer, and yes I am agree also your horn high driver go to 500 hz and that makes it more easy, my has to go to 1000 a 1200 hz for tweeter use in my case.
thanks for the explane of the script I go try later on.
regards
kees
I have done a kind of plug, I do not now what happens when use it it fills room of woofer, and yes I am agree also your horn high driver go to 500 hz and that makes it more easy, my has to go to 1000 a 1200 hz for tweeter use in my case.
thanks for the explane of the script I go try later on.
regards
kees
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Putting a volume filler in the chamber that is negative space of cone is a well used trick. It should work - you can mold one out of plaster.
Here is a JBL array that uses a cone shaped filler with slots in it for their mid driver on the RBI (synergy-like line array).
RBI
Here is a JBL array that uses a cone shaped filler with slots in it for their mid driver on the RBI (synergy-like line array).
RBI
An externally hosted image should be here but it was not working when we last tested it.
What I scared for is that it give a problem with the simmed port itselfs, makes it longer in wave sense or worse, that is why have it done this way, when now the volume of the filler I can adjust VTC for it and see what happens, for my I think I need it, this because I use a woofer until 1200 hz or so, and it does if vtc is not to large..
so this is good idea, and also the example you give, a wood ladge do wunders, I now one for sale very sheap.
regards
so this is good idea, and also the example you give, a wood ladge do wunders, I now one for sale very sheap.
regards
Kees,
Why don't you use a fullrange driver like me to avoid having the woofer go to 1khz? You will get inter modulation distortion with making woofer cover such a broad range. That will solve several problems because the woofer has to move a lot to make bass and asking it to make 1khz on top may be asking for distortion on HF part.
Why don't you use a fullrange driver like me to avoid having the woofer go to 1khz? You will get inter modulation distortion with making woofer cover such a broad range. That will solve several problems because the woofer has to move a lot to make bass and asking it to make 1khz on top may be asking for distortion on HF part.